The manufacture of articles formed of webs that require some reinforcement to withstand forces experienced during use are known. In many cases, reinforcement is simply provided over the entire substrate or web. Such approaches can, however, add cost and weight to the web, as well as stiffness over the entire surface of the web—even in those areas that do not require reinforcement. Furthermore, reinforcing layers that are coextensive with the web may also reduce its breathability.
To address some of these issues, smaller pieces of reinforcing materials may be attached to a web or substrate in selected areas that require reinforcement. The handling and attachment of such discrete pieces can, however, be problematic, by potentially reducing throughput, causing waste (where the discrete pieces are not securely attached), requiring precise registration or location on the web, requiring the use of adhesives or other bonding agents, etc. The discrete pieces may also present relatively sharp that may be the source of irritation or discomfort. The irritation or discomfort can be exacerbated because the reinforcing pieces are typically located on the surface of the substrate.
In addition to reinforcing substrates or webs, it may also be desirable to manufacture articles that exhibit elasticity in addition to reinforcing regions. The manufacture of articles that exhibit elasticity, i.e., the ability to at least partially recover their original shape after moderate elongation, may be desired for a number of reasons. For example, elasticity may be useful in connection with fastening systems for items such as garments (e.g., diapers, training pants, gowns, etc.). Elasticity in garments can provide what may be referred to as dynamic fit, i.e., the ability to stretch and recover in response to movement by the wearer.
Elasticity may also be useful in connection with other applications. For example, some fasteners may provide more consistent attachment if the fastener is held in tension that can be supplied by stretching the fastener and relying on the recovery forces to provide the desired tension. In other instances, elasticity may allow for easy adjustment of the size or length of a fastener or other article.
Although elasticity may be beneficial in a variety of different applications, it may raise issues in manufacturing. Many attempts to provide elasticity rely on separate elastic components that are, e.g., glued or sewn to a backing or other nonelastic member to provide the desired elasticity. The manufacture of such composite articles may be problematic in that secure attachment of the elastic components may be difficult to achieve and/or maintain. Further, the cost and difficulty of providing and attaching separate elastic components may be relatively high. The handling and attachment of separate elastic components can reduce throughput, cause additional waste (where the separate components are not securely attached), etc.
In other instances, an entire article may be constructed to provide the desired elasticity. For example, many elastic fastening systems rely on the use of elastic laminate backings in which the elastic materials are provided in the form of a film that is coextensive with the backing. Such an approach may add costs associated with providing a coextensive elastic layer or layers. Further, many elastic materials are not breathable. If the elastic laminate backings are to be used in garments, it may be desirable to perforate the backing to improve its breathability. Such additional processing does, however, add to the cost of producing the elastic laminate backing. Another potential disadvantage of elastic laminate backings is that it may be difficult to provide any variability in the elastic recovery forces generated in different portions of the backing.